The coastal conservation agency estimated that 450,000 cubic meters of sand would be needed to nourish the beach.
International bids would be called for dredging sand from a deep sea sand mine.
To reduce the frequency of re-nourishment a few off shore breakwaters would also be built.
The agency estimated the project to cost about 350 million rupees.
In the past Sri Lanka has used hard structures including rock, which disfigures beach areas and could also shift erosion to adjacent areas, by redirecting energy.
Sri Lanka's Western Coastal areas which face strong monsoon winds have been particularly susceptible to sea erosion in the past.
In many Asian nations, human activities such as destruction of mangroves for prawn culture have worsened erosion.
Minister Rambukwelle said the cabinet of ministers has approved a plan by the island's Coastal Conservation Department to combat sea erosion in Marawila with sand nourishment.
A note to cabinet said sand nourishment will not only